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Foam insulation- add more later?

Troubleshooter | Posted in Energy, Heating & Insulation on January 31, 2021 01:09pm

Can I have 4″ of hd foam sprayed on the bottom of the roof decking? Then come back years later and add more?
Also if I put the intumescent coating or just latex paint, can foam be added on top of that?

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Replies

  1. Sm_raudales | Feb 11, 2021 04:23pm | #1

    Can I Add New Insulation Over Old Insulation?

    Yes! You can absolutely new insulation over old insulation… as long as it isn’t wet.

    If it… appears that the insulation [is wet or] has previously been wet, you should look for the cause and repair the problem to prevent a reoccurrence. Remove any wet insulation. Wet insulation can lead to mold, mildew, or even the rotting of your ceiling or roof rafters.”

    In fact, you can add new insulation over the existing installation in other areas of your home, not just the attic. And you don’t even have to choose the same material used in your existing insulation.

    Rather, you should decide on the material that best meets your current needs, considering all of the following:

    Energy efficiency
    R-values (effectiveness of the insulation)
    Your budget
    Any health concerns you might have
    Durability of the insulation material
    Eco-friendliness of the material
    Things to Keep in Mind When Installing New Insulation Over Existing Insulation
    You have a few choices about the type of insulation you might install atop your old insulation:
    Batt insulation
    Rolled insulation

    1. Troubleshooter | Feb 12, 2021 09:24am | #2

      If you spray foam on top of foam can the old foam be painted?

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